# Define here the models for your spider middleware
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html
import random

from scrapy import signals
from fake_useragent import UserAgent

# useful for handling different item types with a single interface
from itemadapter import ItemAdapter
from scrapy.core.downloader.handlers.http11 import TunnelError

from util import proxies
from util.proxies import get_proxies, get_proxy_poll


class TutorialSpiderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the spider middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_spider_input(self, response, spider):
        # Called for each response that goes through the spider
        # middleware and into the spider.

        # Should return None or raise an exception.
        return None

    def process_spider_output(self, response, result, spider):
        # Called with the results returned from the Spider, after
        # it has processed the response.

        # Must return an iterable of Request, or item objects.
        for i in result:
            yield i

    def process_spider_exception(self, response, exception, spider):
        # Called when a spider or process_spider_input() method
        # (from other spider middleware) raises an exception.

        # Should return either None or an iterable of Request or item objects.
        pass

    async def process_start(self, start):
        # Called with an async iterator over the spider start() method or the
        # maching method of an earlier spider middleware.
        async for item_or_request in start:
            yield item_or_request

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)


class TutorialDownloaderMiddleware:
    # Not all methods need to be defined. If a method is not defined,
    # scrapy acts as if the downloader middleware does not modify the
    # passed objects.

    @classmethod
    def from_crawler(cls, crawler):
        # This method is used by Scrapy to create your spiders.
        s = cls()
        crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
        return s

    def process_request(self, request, spider):
        # Called for each request that goes through the downloader
        # middleware.

        # Must either:
        # - return None: continue processing this request
        # - or return a Response object
        # - or return a Request object
        # - or raise IgnoreRequest: process_exception() methods of
        #   installed downloader middleware will be called
        return None

    def process_response(self, request, response, spider):
        # Called with the response returned from the downloader.

        # Must either;
        # - return a Response object
        # - return a Request object
        # - or raise IgnoreRequest
        return response

    def process_exception(self, request, exception, spider):
        # Called when a download handler or a process_request()
        # (from other downloader middleware) raises an exception.

        # Must either:
        # - return None: continue processing this exception
        # - return a Response object: stops process_exception() chain
        # - return a Request object: stops process_exception() chain
        pass

    def spider_opened(self, spider):
        spider.logger.info("Spider opened: %s" % spider.name)


ua = UserAgent()


class TutorialUserAgentMiddleware:
    def process_request(self, request, spider):
        # request.headers['user-agent']=ua.random
        pass

    def process_response(self, request, response, spider):
        return response


cookies = ['aaaaaaaaaaaa1', 'aaaaaaaaaaaaa2', 'aaaaaaaaaaaa3', 'aaaaaaaaaaa4']


class TutorialRandomCookieMiddleware:
    def process_request(self, request, spider):
        request.headers['cookie'] = f'sessionid={random.choice(cookies)}'
        pass

    def process_response(self, request, response, spider):
        return response


class ProxiesMiddleware:
    @classmethod
    def from_crawler(cls, crawler):
        s = cls()
        s.settings = crawler.settings
        return s

    def process_request(self, request, spider):
        proxy = random.choice(self.settings['PROXIES'])
        request.meta['proxy'] = proxy

    def process_response(self, request, response, spider):
        return response


class ProxiesPollMiddleware:
    @classmethod
    def from_crawler(cls, crawler):
        s = cls()
        # s.proxy_poll = get_proxy_poll(1)
        s.proxy_poll = []
        return s

    def process_request(self, request, spider):
        if len(self.proxy_poll) == 0:
            self.proxy_poll.append(get_proxies())
        proxy = random.choice(self.proxy_poll)
        request.meta['proxy'] = proxy['http']
        print('使用代理', proxy['http'])
        request.meta['ip'] = proxy

    def process_response(self, request, response, spider):
        return response

    def process_exception(self, request, exception, spider):
        if isinstance(exception, TunnelError):
            ip = request.meta['ip']
            print(exception, '代理异常', ip['http'])
            if ip in self.proxy_poll:
                self.proxy_poll.remove(ip)
                self.proxy_poll.append(get_proxies())
            if len(self.proxy_poll) == 0:
                self.proxy_poll.append(get_proxies())
            ip = random.choice(self.proxy_poll)
            request.meta['proxy'] = ip['http']
            request.meta['ip'] = ip
            return request


class TennlProxiesMiddleware:

    def process_request(self, request, spider):
        tunnel = "h560.kdltpspro.com:15818"
        username = "t16308821704879"
        password = "7cv5nz3m"

        request.meta['proxy'] = "http://%(user)s:%(pwd)s@%(proxy)s/" % {"user": username, "pwd": password,
                                                                        "proxy": tunnel}
        request.headers["Connection"] = "close"

    def process_response(self, request, response, spider):
        return response
